Supervised alarm system



Nov. 7, 1967 N. J. VIETZ SUPERVISED ALARM SYSTEM 2 Sheets-Sheet l FiledMay 19, 1965 ATTORNEY Nov. 7, 1967 N. J. VIE-rz 3,351,934

SUPERVISED ALARM SYSTEM Filed May 19, 1965 2 Sheets-Sheet 2 ATTORNEY3,351,934 SUPERVISED ALARM SYSTEM Norman J. Vietz, Brooklyn Center,Minn., assignor to Honeywell Inc., Minneapolis, Minn., a corporation ofDelaware Filed May 19, 1965, Ser. No. 456,934 9 Claims. (Cl. 340-409)ABSTRACT y F THE DISCLOSURE A direct current energized alarmsystem usinga pair of conductors between a protected area and a supervised remotereceiving panel. The direct current in conjunction with a polarizedrelay means and a polarity reversing means permits continuoussupervision for faults and when necessary transmits alarms from theprotected area.

The present invention is directed generally to an alarm system, and moreparticularly is directed to an alarm system that is capable of completesupervision of the conductors that connect a remote receiving panel tothe areas protected, as well as, provide transmission of coded alarm andtrouble signals. y

Alarm systems, and particularly re and similar alarm systems, haveIbecome very highly developed due to the exacting demands of the usersas well as rating organizations and related groups. Due to therequirements that have developed, tire alarm systems have become verysophisticated. The systems require that a differentiation be readilymade between an actual fire or alarm condition, and various faults ordefects that can and do occur in the components of the systems. Further,the present day tire alarm systems require that a coding be provided sothat the location of a lire or fault can be readily detected from aremote area or location. In order to accomplish all of these functionsin an economical fashion, it becomes paramount that Iunusual types ofcircuits be developed. A further stringent requirement on systems thatutilize alarms to protect areas and transmit this information back to acentral or remote panel is concerned, is the utilization of a minimumnumber of wires. Due to the ready availability of telephone circuits,many of the systems have been developed utilizing a two conductor pairof telephone wires between the remote area where the monitoring occurs,and the protected area where the alarm or iire originates. A

The present alarm system is primarily directed to a sophisticated rlirealarm or similar type of alarm syste-m that is capable of utilizing apair of telephone conductors between the remote area where the alarmpanel is located and the protected area where the sensors or alarmgenerating contacts are located. The system must be capable ofgenerating a coded alarm, thereby pin pointing the specific operatorpanel or location from which the alarm is emanating, as well as, a codedor noncoded trouble signal to indicate the existence of one or anotherdifferent fault conditions. The fault conditions normally protectedagainst are an open line between the remote area and the protected area,a grounding of the conductors or pair of conductors between the remotearea and the protected area, a direct short circuit in the pair ofconductors, or some mechanical or electrical fault in the protected areathat requires correction for the system to operate in a fully normal andacceptable fashion. While a number of systems exist that will meet manyof the conditions out? lined above, the systems now in existencenormally are deficient in being able to supply all of the desiredinformation over a single pair conductors and provide full supervisionof coded trouble and alarm signals.

It is the primary object of the present invention to dis- United StatesPatent O 3,351,934 Patented Nov. 7, 196.7

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close an alarm system that utilizes a single pair of conductors betweena coded remote receiving panel and a protected area, and which willfully supervise the conductors against faults as well as transmitelectrically separate coded trouble and coded alarm signals.

A further object of the present invention is to disclose an alarm systemthat utilizes conventional alarm equipment and components that arereadily available and can be adapted to use in the system without greatexpense beyond that normally incurred in their usual installation anduse.

Yet another object of the present invention is to disclose an alarmsystem that can transmit both coded trouble signals and coded alarmsignals over a single pair of telephone conductors between the protectedarea and the coded remote receiving panel at a remote area.

A still further object of the present invention is to disclose an alarmsystem that provides complete supervision of a pair of conductors andwhich is capable of transmitting an alarm signal even though one of theconductors is either open circuited or grounded, and which is furthernot completely incapacitated even by a short circuit across the pair ofconductors.

These and other objects will become apparent when the drawings are fullyconsidered along with the following description, wherein: y

FIGURE 1 is a semi-schematic circuit of the system in its very simplestform and which is utilized to explain the invention in its rudementaryform, and;

FIGURE 2 is an actual schematic of a system for commercial use andinstallation, and which incorporates the invention.

In the present description of FIGURES 1 and 2 the same referencenumerals will be utilized in each of the figures for identification ofcorresponding parts. Many 'of the components are conventional electricalcomponents and will be described or discussed in connection with theindividual circuits in which they are active.v K

A description of the semi-diagrammatical arrangement of FIGURE 1disclosing the heart of the invention will be undertaken as a preface tothe detailed disclosure of FIG- URE 2. In FIGURE 1 a direct currentsource means 20 is connected by conductors 21 and 22 to terminals 1 and2 of a coded remote receiving panel generally disclosed at 23 by thedashed box or outline. Powered from terminals 1 and 2 there isdisclosed. generally a relay responsive control means 24 that includes aconductor 25 connected to terminal 2 anda conductor 26 connected to aterminal 5 that is directly connected to terminal 1. It is thus obviousthat conductors 25 and 26 supply a direct current source of supply tothe relay responsive control means generally disclosed at 24.

The relay responsive control means 24 incorporates a number ofconventional electrical components such as resistors, capacitors,diodes, switches, relay contacts, relay coils, and associated circuitry.All of this circuitry will be described in some detail in connectionwith FIGURE 2, but at the present time all that need be indicated isthat the relay responsive control means 24 incorporates the relay coilsfor a group of relays K1, K2, K3, K4, K5, K8, and a time delay relayTDR. The relay responsive control means 24 lalso incorporates a numberof contacts associated with the respective relays, as well as, contactsassociated with two additional relays K6 and K7 that will be locatedsubsequently. It will -be noted that relay K1 incorporates one normallyopen contact K1-1. The relay K2 incorporates or operates four normallyopen relay contacts K2-1, K2-3, KZ-S, and K2-7. Relay K2 also operatesthree normally closed contacts KZ-Z, K2-4, and K2-6. The relay K3utilizes eight contacts two of which are not shown. The contactsutilized in the present disclosure at some point are the normally closedcontacts K3-2, K3-4, and K3-6, while .the relay K3 incorporates thenormally open contacts K3-3 and K3-S. The relay K4 incorporates twonormally open `and two normally closed contacts with contacts K4-1 andK4-3 being normally open and K4-2. and K4-4 being normally closed. Therelay K5 incorporates six contacts with the contacts K5-1, K5-3, K5-5,and K5-6 being normally open while contacts K5-2 and K5-4 are normallyclosed. The relay K8, which is also incorporated in the relay responsivecontrol means 24, incorporates two normally open contacts KS-l and KS-Sand a single normally closed contact K8-2. The balance of the -relayfunction within the rellay responsive contro-l means 24 is handled by atime delay relay TDR that has a normally closed contact TDR-1 and anormally open contact TDR-2.

The various combinations of energization and function of the relays andtheir associated contacts and components allow the presently discloseddevice to perform a large group of functions, each of which will bedetailed in connection with FIGURE 2. A Ifurther description of FIGURE lat this point will clarify the broad object and embodiment of thepresent invention.

The four contacts of relay K4 and their associated circuitry yield acircuit polarity reversing means 30 shown in a dotted box. The circuitpolarity reversing means 30 incorporates the normally closed contactsK4-2 and K4-4 and a pair of normally open contacts K4-'1 and K4-3, alongwithfa pair of reversing conductors 31 and 32 to provide a reversal ofthe direct current source potential between the input points 33 and 34and the output points 35 and 36. These contacts could be replaced by amultivibrator circuit or oscillator, if desired. The output point 35 isconnected to an output terminal 3 of the coded re- `mote receiving panel23. The point 36 `is connected to a polarized relay means generallydisclosed at 40 and which is made up of a pair of series connectedrelays K6 and K7 that are respectively paralleled by diodes orasymmetric current conducting means CR1 and CRZ, with the diodes CRI andCRZ polarized in opposite directions. The polarized relay means 40 hasan output point 41 which is connected to terminal 4 of the coded remotereceiving panel 23. While the polarized relay means 40 has beendisclosed as a pair of series connected relays K6 and K7 that are inturn paralleled by diodes CR1 and CRZ, the polarized relay means 40could be any type of polarized relay that is capable of polarizedoperation. By that it is meant that the current passing through thepolarized relay means 40 in one 'direction would operate the relay inone manner, whilecurrent passing through the relay 40 in the oppositedirection would cause a reverse operation. It is further meant that withno current flowing the relay means 40 would assume a neutral position.Also the diodes could be placed in series with the relays K6 and K7 andthen they could be connected in series. The simplest arrangement of thistype of relay is as disclosed utilizing two conventional relays that arepolarized by diodes, but the relay means 40 could be a conventionalthree position relay with magnetic polarizing means. Throughout thepresent speclcation whenever the terminology diode is utilized it isunderstood that the term is used in its broadest sense as an asymmetriccurrent conducting means.

Further associated with the coded remote receiving panel 23 and directlyconnected to the relay responsive control means 24 is a signal means 42connected by appropriate conductors 43, 44, 45, and 46 to the relayresponsive control means 24. The signal means 42 can be any type ofaudio or visual signal means such as a bell, buzzer, recorder, orregister that is operated in response to the relay functions that occurin the relay responsive control means 24. The specific signal meanslfunctions will be described in detail when FIGURE 2 is discussed.

The output terminals 3 and 4 of the coded remote receiving panel 23 areconnected to a pair of conductors 5()` and 51 that are under constantsupervision of their condition by means of the coded remote receivingpanel 23. The supervised pair of conductors 50 and 51 normally would betelephone wires or similar Qoadutors between the coded remote receivingpanel 23 and a remote protected area generally disclosed by the dottedbox 49 and which represents the interior of a building or any other areato which the present alarm system is applied. The conductors 50 and 51are connected at terminals 52 and 53 to an alarm actuated means 54 thathas been generally disclosed. The alarm actuated means 54 in fact isgenerally an alarm actuated switching means or is sometimes referred toas an operator or transmitter panel 54. The alarm actuated means 54contains a number of switches and components that respond in a speciedmanner in the case of the transmission of a trouble or alarm condition.The arrangement and function will be discussed below. Terminals 52 and53 are -connected to conductors 55 and 56 that pass through a pair ofnormally closed contacts 57 and 5S to outlet terminals 60 and 61 for thealarm actuated means 54. Connected between conductors 55 and 56 are thenormally open contacts 62 and a diode CRS. The diode CRS is polarized soas to oppose any current llow if the potential between conductors 55 and56 is from plus to minus. Also connected to conductor 55 is a normallyopen contact 63 that is -connected to a terminal 64 that is grounded at65.

When an alarm actuates the alarm actuated means 54 the contacts 57 and5S open, contact 62 closes and approximately milliseconds later contact63 closes. In the case of the transmission of a coded trouble signalalone, the contact 57 only would be operated by the alarm actuated means54. The exact result of this operation will be discussed subsequently.Connected between terminals 60 and 61 of the alarm actuated means 54 isa terminating impedance in the form of a diode CR7. The diode CR7 ispolarized in an opposite direction to the diode CRS.

Operation of FIG URE 1 The circuit disclosed in FIGURE 1 is in itsoperating condition as disclosed. In this condition the pair ofconductors 50 and 51 is being supervised with no alarm condition ortrouble condition existing in the protected .area 49 which encompassesthe alarm actuated means 54. Under these conditions a direct currentflows from source means 20 through the closed contact K4-2 overconductor 50 through the closed contact 57 and through the diode CR7back directly to the supervised conductor 51. The supervised conductor51 supplied this direct current flow to the polarized relay means 40where the current passes through the diode CRZ and then passes throughthe relay coil K6 to energize this portion of the polarized relay means40. The current then ilows back through the closed relay contact K44 tothe direct current source means 20. With the energized relay coil K6,through its contacts K6-1 and K6-2 which are normally open and normallyclosed respectively (FIGURE 2), the relay responsive control means 24senses a normal condition with current flow through the conductors 50and 51 and no alarm or trouble condition. This is the normal orsupervised state of the device.

Should a re be detected by the alarm actuated means 54, the contacts 57and 58 opened along with the subsequent closing of the contacts 62 and63. It is thus apparent that the diode CR7 is removed from the circuitand the reverse polarity diode CRS is placed in the circuit as theterminating impedance for wires 50 and 51. Approximately 100milliseconds later the positive side of the direct curlrent source means20 is also grounded at 65. This grounding completes a circuit to agrounded conductor 66 of the relay responsive control means 24 if relayK6 is energized (K6-1 closed) or relay K3 is de-energized (K3-2) closed.

As soon as the diode CRS is placed across the conductors 50 and 51, thecurrent flow through the conductors` 50 and 51 temporarily ceases. Thelack of current flow through K6 causes the relay K6 to respond byopening:

its normally open contact which causes the circuit polarity reversingmeans 30 to operate thereby reversing the con-- CR8 is properlypolarized to carry current through the supervising pair of conductors 50and 51 in a reverse direction to that originally carried during normaloperation without an alarm. The reversal of current flow in conductors50 and 51 causes the relay K6 to be bypassed through the diode CRl butpulls in the relay K7 of the polarized relay means 40. The operation ofthe relay K7 of the polarized relay means 40 places the relay responsivecontrol means 24 in condition to receive an alarm signal. The alarmsignal is normally coded by momentarily opening and closing the contacts59 and 62. This opening and closing of the contacts does not allow thebalance 4of the relay circuit in the relay responsive control means 24to drop out as the contacts are open for a short enough period of time,normally four-tenths (.4) of a second. An appropriate relay (K3 inFIGURE 2) in relay responsive control means 24 has approximately aonesecond delay in drop out time thereby responding to the codinglapplied by opening and closing of the contacts 57 and 62 in the circuitto remain energized.

The present circuit also senses the presence of a coded trouble fromt-he alarm actuated means 54 by operation of the contact 57 in anintermittent coded manner. The coded operation of contact 57 opens andcloses the normal current ow through the relay K6 which allows the relayto operate contacts in the relay responsive control means 24 to indicatea coded trouble signal. In addition to the alarm and trouble signalsfrom the alarm actuated means 54, the supervision of conductors 50 and51 protects this system against Ian open circuit, in the same fashion asintermittently opening and closing contact 57. An open circuit ofconductor 50` or 51 for more than approximately one second would be atrouble signal of a continuous fault nature rather than a coded nature,thereby differentiating it rfrom a coded trouble signal being sent bythe alarm actuated means 54. A grounding of the conductors 50 or 51 orthe shorting of the conductors 50 and 51 can also be sensed by the relayresponsive control means 24 due to the nature of the current flows ofthe two directions or the polarized directions by means of the polarizedrelay means 40. This will be brought out in detail in connection withthe description of the device disclosed in FIGURE 2.

At this point a brief statement of the heart of the present invention isbelieved in order. It is obvious that a direct current energizing means20 is supplied to a coded remote receiving panel 23 that has a circuitpolarity reversing means 30 that is connected by a pair of supervisedconductors through a terminating impedance CR7 in series with apolarized relay means 40. The type of current ow, both as to polarityand uniformity is sensed by this arrangement and the proper control isthen obtained by the relay responsive control means 24 along with Vthepolarized relay means 40 to indicate either a trouble signal, an alarmsignal, or some fault on the supervised pair of conductors 50 and 51.This is all accomplished by the use of terminating diodes that areappropriately reversed along with the circuit polarity reversing means30 and the polarized relay means 40 to sense the condition of thesystem.

A complete alarm system has been disclosed in detail in the schematic ofFIGURE 2. Many of the relays, relay contacts, diodes, and other circuitcomponents have been enumerated in connection with the description ofFIGURE l and the same reference numerals will apply to both of thesefigures. The elements contained in the circuit of FIGURE 2 that have notyet been described in detail are conventional electrical components suchas switches, diodes, capacitors, and resistors. The individualcomponents that have not been enumerated to this point in thedescription will be specilically recited when their function is utilizedin the following detailed description of operation of this circuit inits various modes, both normal and abnormal.

FIGURE Z-Normal circuit operation Supervisory circuits-The directcurrent source means 20 is connected to terminals 1 and 2 and the diodeCR7 is connected across the pair of conductors or receiving lines 50 and51 which is ultimately connected between the terminals 3 and 4. Underthese conditions, the coded remote receiving panel 23 will assume itsnormal supervisory condition. The conductors 50 and 51 (shown in FIGURE2 in two sections) may be connected to any number of alarm actuatedmeans or operator panels 54, within some fixed limits of the resistanceof the lines 50 and 51.

A supervisory circuit exists from terminal 1 by means of conductor 26through relay K3, contact K2-4, conductor 25, terminal 2, and back tothe direct current source means 20. During a normal supervisorycondition, relay K3 is energized which causes the contact K3-4 to openand contact K3-3 to close, thereby completing the supervisory loopbetween the terminals 3 and 4. Under these conditions, a supervisorycircuit exists from the direct current source means 20 by means ofterminal 1, a resistor R1, contact K4-2, contact K3-3, terminal 3,conductor 50, the trouble contact 57, to a series noninterfering contact70 (which will be described shortly) to the end of the line diode CR7through any number of alarm actuated means 54, back through contact 58and conductor 51 to terminal 4. The normal supervisory circuit lfurtheris completed by diode CR2, the relay K6, contact K4-4 and terminal 2back to conductor 22 from the direct current source means 20. It is thusapparent that a complete series circuit carrying current under normalsupervisory conditions exists. As was previously stated, a seriesnon-interfering contact 70 was mentioned. vThe Contact 70 along with thepreviously mentioned contact 58 and a contact 71 and diode CR9 completea normally utilized contact arrangement referred to as a Yseriesnon-interfering contact. In the alarm art, a series non-interferingcontact arrangement is a contact arrangement that when operated,terminates the alarm actuated means 54 in a fashion as if it were thelast alarm actuated means in the entire series. In eiect, when the'alarm actuated means 54 operates, contacts 70 and 58 open with contact71 then closing. This places an end of the line diode. 'CR9 in thecircuit to replace the diode CR7 ,as if the diode CR9 was the linalterminating impedance. This is a standard alarm. technique and is usedto isolate the location of a trouble or alarm signal. This will bebrought out in more detail in the description, as the description of theoperation of various modes is completed.

With the supervisory circuit just described, the current ow through theloop or circuit is sufficient to energize the relay K6 but the voltagedrop across the diode CR?. is insufficient to pull in the relay K7. Whenpower is ap# plied, there is a possibility that relay K2 could pull inbefore the relays K3 and K6, because of the series connection to relayK2 through the contact K6-2. In that case, the operation would beindicated by a trouble buzzer 75 operating in the signal means 42 due tothe premature operation of the relay K2 with either contact K2-6 or KZ-Sand a trouble silence switch 74 having contacts S2-1 and S2-2. Thetrouble silence switch 74 is connected in series with a terminal 6 andthe trouble buzzer 75 across conductors 25 and 26 from the directcurrent source means 20. In the case of the premature operation of relayK2, the trouble buzzer 75 will sound, a trouble light DS2 which isconnected by contact K2-3 across the direct current source means 20would light, and relay K4 would be energized along with the relay K2.This condition can be readily corrected at startup by the operation yofa manual reset switch S3-1 which is placed around the contact K2-4 andin series with the relay K3 for energizing the relay K3 for resetpurposes. By pushing the reset switch S3-1, the relay K3 is energizedand the energization of this relay will in turn cause relay K6 toenergize if the alarm lines 50 and 51 are in a normal condition. Whenrelay K6 energizes, relay K2 will de-energize due to the opening of thenormally closed contact K6-2. At this time the trouble buzzer 75 willbecome silent and the trouble light DS2 will go out. At this point thecircuit is in normal supervisory condition with the current -ow in theconductors 50 and 51 through the terminating diode CR7.

Trouble signals.-A trouble signal arriving at the coded remote receivingpanel 23 may be a non-coded or continuous fault signal or a codedsignal, depending on the type of trouble and its location. A continuousfault trouble signal can be caused by an open alarm line 50 or 51, or asuiciently long (more than one second) opening of contact 57 of thealarm actuated means 54. When an open line occurs, relay K6de-energizes. When relay K6 de-energizes, relay K2 energizes throughcontact K6-2 to cause the trouble light DS2 to be turned on along withthe sounding of the trouble buzzer 75 in the signal means 42. The relayK3 is also de-energized by the operation of relay K2 if the troublecondition exists for more than approximately one second. This one seconddelay is created by the capacitor C2 and the resistor R3 which forms anRC network around the relay K3 to keep it energized for the one second.This one second delay is utilized to prevent momentary power disruptionsfrom signalling a trouble on the system. When relay K3 drops out,contact K36 connects the conductor 25 through contact K8-2 to the timedelay relay TDR. Contact K3-6 also causes the energization of relay K4through the diode CR6. The operation of relay K4 is a critical operationin the present device as it in turn operates the circuit polarityreversing means 30 that encompasses the contacts K41, K4-2, K4-3, andK4-4. The operation of relay K4 and the circuit polarity reversing means30 changes the polarity of the voltage available to the relay K7.

About ten seconds after energization, the time delay TDR will cause itsContact TDR-1 to open. After about one minute of the supplying of powerto the time delay relay TDR, contact TDR-2 will close causing relay KSto be pulled in and relay K8 will lock itself in through its own contactK81. At the same time, contact K8-2 takes power ot the time delay relayTDR. When relay K8 makes, contact K8-3 is in series with the time delayrelay contact TDR-1 which again closes in about ive minutes and relay K3is energized. When the relay K3 energizes, Contact K3-3 closes, contactK3-4 opens, contact K3-6 opens and this sequence restores the alarm linecircuitry to the normal condition and de-energizes relay K8. K3 isdelayed in dropout by the diode CRS in parallel with K8. If at this timethe alarm line has been restored to a normal condition, the relay K6will energize causing the relay K2 to drop out and relay K3 to remainenergized, and the coded remote receiving panel 23 will be returned tonormal. It the alarm line has not been returned to its normal condition,relay K6 will not pull in and the relay K3 will de-energize about onesecond after relay K8 has de-energized. The above described action iscalled the automatic reset action of the coded remote receiving panel23. The time delay relay will complete a heating-cooling cycleapproximately every five minutes until the panel is reset. Thisarrangement provides for complete reset of the device when the troublethat has started the sequence has been removed.

A coded trouble signal is received from a coded trouble contactarrangement contained in the alarm actuated means 54. The coded troublecontact arrangement is the contact 57 as disclosed in the alarm actuatedmeans 54. The alarm actuated means 54 has a pair of seriesnoninterfering contacts 70 and 5S which open and place the diode CR9 inseries with the trouble contact 57 to eliminate any possibility ofreceiving a jumbled code from any unit further down the lines 50 and 51.When the coded signal contact 57 opens, the relay K6 drops out causingthe relay K2 to energize and the relay K4 to reverse the polarity of thelines to terminals 3 and 4 for about 25 milliseconds. When relays K2energizes, the trouble light DS2 operates along with the trouble buzzer75. When the trouble contact 57 in the operator panel returns to thenormal or closed position, relay K6 energizes again to cause relay K2 tode-energize and the trouble light DS2 and the buzzer 75 are silenced.This same sequence will recur for every opening and closing of thetrouble contact 57 in the alarm actuated means 54. By operating thetrouble contact 57 in a particularly coded sequence depending on whichalarm actuated means 54 is operated, a coded trouble signal isdeveloped. It should be noted, that the relay K3 does not drop out forabout one second after contact K2-4 opens, so that for a normal codedround or sequence of signals, relay K3 will remain energized. When thealarm actuated means 54 panel is through with the coded trouble signal,the receiving line is returned to normal andthe coded remote receivingpanel 23 automatically returns to its normal condition.

In the present arrangement a normal code is approximately 0.4 second onand 0.4 second oth When an alarm actuated means 54 goes into acontinuous fault trouble condition or the alarm line opens, the troublebuzzer 75 may be silenced by moving the trouble switch 74 from positionS2-2 to S21. This trouble silence switch has a ring-back featurebuilt-in so that when the panel is reset manually or automatically, thebuzzer will sound if the panel is in a normal position, but the troublesilence switch is in an olf-normal position.

Alarm signal.-Before describing the coded action at the remote receivingpanel 23 for an alarm signal, the coding action of the operator panel oralarm actuated means 54 will be described. An alarm signal istransmitted from the V alarm actuated means or operator panel 54 withthe series non-interferring contacts 58 and 70 opening the connection toall circuits electrically further from the alarm actuated means oroperator panel 54, and closing a contact 71 in series with a diode CR9that forms the terminating impedance for the circuit at that point. Thispart of the alarm signalling action does not effect any action of thecoded remote receiving panel 23 because the relay K3 will tolerate a onesecond open circuit in the line before it operates. The alarm codingaction begins with the trouble contact 57 opening and the normally openalarm contact 62 in series with the diode CRS closing. The time betweenthe yopening of the trouble contact 57 and the closing of the alarmContact 62 in series with the diode CRS is in the order of a fewmilliseconds. The normally open contact 63 to the ground closesapproximately 100 milliseconds after the normal open alarm contact 62 inseries with the diode CRS has closed.

The alarm signal arriving at the coded remote receiving panel 23 willcode the trouble buzzer 75 and light DS2 along with the operation of analarm bell or hom 76 and the alarm light DS1. The trouble contact at theoperator panel or alarm actuated means 54 in opening causes relay K6 tode-energize which .causes the relay K2 to energize. When relay K2energizes, the trouble light DS2 and the trouble buzzer 75 sound, alongwith operation of the contact K2-1 which causes the relay K4 to energizeduring the RC time of the capacitor C3 and R4 thereby operating thecircuit polarity reversing means 30. When the alarm contact 62 in serieswith the diode CRS in the alarm actuated means 54 closes, relay K7energizes due to the reversal of polarity caused by the operation of thecircuit polarity reversing means 30 under the action of relay K4. Whenthe relay K7 energizes, relay contacts K7-1 cause the relay K5 toenergize. The operation of relay K5 in turn causes the alarm horn orbell 76 to sound, the alarm lights DS2 to light, and contact KS-S tooperate which causes relay K4 to keep the line polarity reversed,thereby holding the relay K7 in an energized condition. When theoperator panel or alarm actuated means 54 has contact 63 closed toground, there would be no further action at the coded remote receivingpanel 23 at this time because the coded remote receiving panel 23 is ina normal operating condition.

When the alarm actuated means 54 opens the ground contact 63, there willbe no panel operation. When the alarm contact 62 in series with thediode CR8 opens, relay K7 will de-energize. The de-energization of relayK7 causes relay K to de-energize causing the relay K4 to deenergize.This action also turns the alarm horn or bell 76 oil and extinguishesthe alarm lamp DS1. When the alarm actuated means 54 or trouble contacts57 close, the relay K6 is energized causing the relay K2 to deenergize,which turns the alarm light DS1 off and silences the trouble buzzer 7S.This action is repeated over and over again for all alarm codes. Itshould be pointed out that relay K3 does not de-energize during the timebecause of its holding action caused by the RC network formed by thecapacitor C2 and the resistor R3.

Abnormal circuit operation Abnormal circuit operation occurs when anoperator panel or alarm actuated means 54 tries to transmit or sendlsignals with a single line fault. A line fault is considered to be anopen line, a grounded line, or a shorted line. Explicitly, a shortedline means a short circuit somewhere between the terminals 3 and 4 andthe end of the line diode CR7.

Supervisory crcuts.-The receiving panel 23 will have a supervisorycircuit for an open line, a grounded line, or a shorted line. Whenreferring to a supervisory circuit, it is meant that either a circuitwill exist or will not exist but that the coded remote receiving panel23 will respond to these conditions. When an open line occurs, relay K6will drop out which causes relay K2 to energize, and the trouble buzzer75 and trouble light DS2 will be operated. Approximately one secondlater K3 drops out. This action, as pointed out before, starts theautomatic reset feature of the receiving panel 23. During the open linecondition, the alarm line is not supervised, but is able to transmit analarm signal, as will be noted later.

When a ground occurs on an alarm receiving line such as conductors 50 or51, relay K1 is energized from the positive side of the direct currentsource 20 through a ground connection to terminal G, through the relaycoil K1 itself, through a parallel arrangement of a capacitor C1 and aresistor R2 and a diode CR4 through the relay contact K6-1 to thenegative side of the direct current source means 2t). When the relay K1energizes, contact K1-1 energizes the relay K2. Contact K2*1 closescausing the relay K4 to momentarily operate the circuit Polarityreversing means 30 to reverse the polarity of the alarm line which inturn causes the relay K6 to be de-energized. When the relay K6 is.de-energized, contact K6-1 opens causing the relay K1 to bede-energized which in turn causes the relay K2 to be de-energized. Atthis point the whole cycle starts over again with the relay K1energizing through the capacitor C1 and contact K6-1 which is once againclosed. The only difference is that there is a slight charge on thecapacitor C1. The capacitor C1 continues to charge with each round orrelay energizing and deenergizing until a point is reached where relayK1 will not energize again. The end result is that the direct currentsource means 20 is placed across the capacitor C1 and relay K1 isde-energized. During the time that the relay K1 is energizing andde-energizing, the trouble light DS2 and the trouble buzzer 75 arepulsing on and off through the action of the relay K2. It takesapproximately two seconds for the capacitors C1 to charge, but K1operates for about 0.4 second.

If the alarm line connected to terminals 3 and 4 is shorted, there willbe no indication. A short circuit between the lines 50 and 51 will notinterfere with the reception of a coded alarm signal, but eliminates thealarm line supervised circuit. As long as the coded remote receivingpanel 23 is capable of receiving a coded alarm with a shorted pair ofconductors, the alarm system is an acceptable system since it providesthe necessary protection even though a fault does in fact exist.

Trouble signals.-A trouble signal (coded), may or may not be transmittedduring a fault condition depending on the type of fault and the place onthe line that the fault occurs. The receiving panel 23 will not receivea coded trouble signal from an operator panel or alarm actuated means 54if there is an open line between the receiving panel 23 and any'alarmactuated means 54 that attempts to send a coded trouble signal. The openline will be indicated at the receiving panel as a continuous faulttrouble signal.

A grounded line will not affect in any way the transmission of a codedtrouble signal. The receiving panel 23 will not receive a coded orcontinuous fault trouble signal if there is a short across the line 5t)and 51 between the receiving panel 23 and the operator panel or alarmactuated means 54 attempting to send a coded or continuous fault troublesignal. A short across the line that is electrically further away fromthe receiving panel than the alarm actuated means 54 or operating panelattempting to send a code will not disrupt the trouble signal.

Alarm sgnals.--The receiving panel 23 will receive a coded alarm signalfor any single fault; open line, grounded line, or shorted line. Thereceiving panel receives a coded alarm signal for an open in the alarmlines 50 or 51. When an open occurs, relay K6 drops out, relay K2 pullsin with relay K3 dropping out after one second and relay K4 pulling in.At this point, the receiving panel Z3 is in emergency signal receivingcondition. As was pointed out before, the automatic reset feature hasbeen actuated. In the emergency signalling condition, relay lK3 hasdropped out and relay K4 has pulled in causing both sides of the alarmline to connect to the positive side of the direct current source means20. The series noninterferring contacts 58, 7G, and 71 will operate asmentioned before. The coded trouble contact portion 57 of the alarmsignalling contacts will have no efrect during the emergency signallingcondition. The alarm contact in series with the diode CRS closes andapproximately milliseconds later the alarm contact 63 to ground closes,causing the relay K7 to energize. The circuit for energizing the relayK7 originates at the positive side of the direct current source means 20and continues through the resistance R1, contact K4-1, diode CRI, relayK7, to terminal 4. For this point there is a parallel path down throughthe alarm line to the alarm actuated means or operator panel 54. Ofcourse, the open line could occur in one of these two paths but thepositive voltage will still reach the alarm contact that shorts toground by the unbroken conductor. Because relay K3 has de-energized,contact K3-2 connects the negative side of the direct current sourcemeans 20 to ground thus completing a circuit to the alarm groundingcontacts 63 of the alarm actuated means S4.

The receiving panel 23 receives alarm signals in the normal manner whenthere is a single ground fault on the alarm receiving lines 5t) or 51.As explained previously, when the ground occurs, there is a short rapidpulsing of the trouble light DS2 and the trouble bell or buzzer 75 willoperate due to the operation of relays K1, K2, K4, and K6. Also, thereceiving panel 23 will operate with a short across the line. A shortacross the line will not be detected at the time it occurs. When thereis a short across the alarm lines 50 and 51 between the receiving panel23 and the alarm actuated means 54, and the means 54 is sending a codedalarm signal, the receiving panel 23 is switched to the emergencyoperating condition by the operation of relay K1. When the operatoralarm contacts make to ground, including the contacts 62 and 63, relayK1 energizes causing relay K2 to energize. When K2 energizes, contactK2-1 causes relay K4 to give a pulsing ll i reversal of polarity to therelays K6 and K7 by the operation of the circuit polarity reversingmeans 30. This reversed polarity pulse is of sufficient duration tocause the relay K6 to de-energize and relay K7 to energize because relayK3 is still energized. When relay K7 energizes, contacts K7-1 energizerelay K5 causing contacts KS-S to close and hold relay K4 in anenergized state. Actually, the time between contacts KZ-l pulling inrelay K4 and the closure of contacts KS-S is shorter than the pulseduration caused by the capacitors C3 and the resistance R4, so relay K4is pulled in and remains locked in through the combination of contacts,the relays K4 and KS along with relay K7 and short across the line.About one second after relay K2 energizes, K3 will drop out causingrelay K7 to drop out which causes relay K5 to drop out. When relay K3dropped out its contacts K3-6 closed to keep K4 energized so thepolarity of the line will remain in the reversed condition or direction.When the alarm contact 63 closes to ground, it will pulse relay K7 whichin turn will pulse relay K5 causing the alarm lamp and trouble bell 76to indicate the alarm. The circuit for pulsing relay K7 is formed fromthe positive side of the direct current source means 20 through theresistor Rd, the contact K4-1, diode CRI, relay K7, and out both ofteminals 3 and 4 in a parallel path down to the alarm actuated means 54through the alarm actuated contact 63 that shorts to ground, and back tothe negative side of the power supply through the ground connection 66at terminal G and contact K3-2. It should be pointed out that the firstone or two pulses of the first group or round of code will be jumbledinto a one second alarm pulse during the time that relay K3 is droppingout. After an alarm has been transmitted to the receiving panel 23 overa shorted line, the receiving panel 23 cannot be reset, which is anindication that a shorted line might exist.

Provided with this equipment is a number of auxiliary contacts operatedby the various relays K2, K3, and K5. These various contacts areconnected Vbetween the terminals 7, 8, 9, 10, 11, 12, 13, 14, and toprovide various coding and auxiliary functions for control of equipmentsuch as recording tapes, alarm lights and any other type of alarmequipment desired. This equipment completes the coded remote receivingpanel 23 in detail.

The detailed description of the operation of various circuits in FIGURE2 have been undertaken as a means of explaining how the invention isapplied to a practical embodiment providing all of the necessaryfunctions to meet the requirements of industry and the ratingorganizations that deal in alarm circuits such as fire alarms. In orderto help clarify the various operations and functions two tables havebeen prepared that summarize various phases of the operation of thealarm system. Table I discloses the state of each of the relays duringVarious phases of operation of the alarm system. Table II provides abrief informal description of the function associated with each relay.

TABLE II General function of the relay The invention, however, iscompletely contained in the circuit contained in broader form inFIGURE 1. Since the present invention can be varied extensivelydepending on what functions are desired, the content of the relayresponsive control means 24 can be varied to include or excludefunctions depending on the complexity desired. As such, in the presentapplication, this section of the device has been referred to broadly asthe relay responsive control means and no attempt has been made tospecifically dene the functions that it will perform as far as theinvention is concerned. The true heart of the invention encompasses manyvariations of the circuitry contained in the relay responsive controlmeans 24 and it forms no specific part of the present invention. Thepresent invention is defined solely by the scope of the appended claims.

I claim as my invention:

1. An alarm system, comprising: direct current source means includingconnection means connected to alarm actuated means in series withpolarized relay means; said alarm actuated means including firstasymmetric current conducting means; said alarm actuated means furtherincluding alarm actuated switching means having second asymmetriccurrent conducting means substituted in place of said first asymmetriccurrent conducting means in reverse polarity upon the operation of saidalarm actuated means; circuit polarity reversing means including saidconnection means connected to said source means to reversibly power saidalarm actuated means and said polarized relay means; and relayresponsive control means and signal means connected by said connectionmeans to said source means and responsive to said operation of saidpolarized relay means to in turn operate said circuit polarity reversingmeans and said polarized relay means to activate said relay responsivecontrol means to thereby operate said signal means.

2. An alarm system, comprising: direct current source 0 means includingconnection means connected to alarm actuated means with first relaymeans and further with second relay means; first diode means in circuitwith said first relay means and second diode means in circuit with saidsecond relay means; said first and second diode means being oppositelypolarized to each other; said alarm actuated means including firstasymmetric current conducting means; said alarm actuated means furtherincluding alarm actuated switching means having second asymmetriccurrent conducting means substituted in place of TABLE I CircuitCondition Relay K1 K2 K3 K4 K5 K6 K7 K8 & TDR

Normal X X Continuous Trouble Signal. X X X Coded Trouble Signal X CodedAlarm X Open Line X X X Grounded Line O O O O & X Coded Alarm W/OpeuLine X X X Coded Alarm W/Grounded Line.. O O & X O & O & Coded AlarmW/Shorted Line X X X O-Pulsed for short time when round first occurs.Codingg X-Energized.

said asymmetric current conducting means in reverse polarity upon theoperation of said alarm actuating means; circuit polarity reversingmeans including said connection means connected to said source means toreversibly power said alarm actuated means and said relay means; andrelay responsive control means and signal means connected by saidconnection means to said source means and responsive to said operationof said first relay means to in turn operate said circuit polarityreversing means and said second relay means to activate said relayresponsive control means to thereby operate said signal means.

3. An alarm system, comprising: direct current source means includingconnection means connected to alarm actuated means in series withpolarized relay means; said connection means including a pair ofconductors over which alarm signals are transmitted and which conductorsare supervised; said alarm actuated means including first asymmetriccurrent conducting means; said alarm actuated means further includingalarm actuated switching means having second asymmetric currentconducting means substituted in place of said first asymmetric currentconducting means in reverse polarity upon the operation of said alarmactuated means; said switching means further including ground circuitmeans to ground said source means upon operation of said alarm actuatedmeans; circuit polarity reversing means including said connection meansconnected to said source means to reversibly power said alarm actuatedmeans and said polarized relay means; and relay responsive control meansincluding a ground connection and signal means connected by saidconnection means to said source means; said relay responsive controlmeans and said signal means responsive to the condition of said pair ofconductors and said alarm actuated means.

4, An alarm system, comprising: direct current source means includingconnection means connected to alarm actuated means with first relaymeans and further with second relay means; first diode means in circuitwith said first relay means and second diode means in circuit with saidsecond relay means; said first and second diode means being oppositelypolarized to e-ach other; said connection means including a pair ofconductors over which alarm signals are transmitted and which conductorsare supervised; said alarm actuated means including first asymmetriccurrent conducting means; said alarm actuated means further includingalarm actuated switching means having second asymmetric currentconducting means substituted in place of said first asymmetric currentconducting means in reverse polarity upon the operation of said alarmactuated means; said switching means further including ground circuitmeans to ground said source means upon operation of said alarm actuatedmeans; circuit polarity reversing means including said connection meansconnected to said source means to reversibly power said alarm actuatedmeans and said first land second relay means; and relay responsivecontrol means including a ground connection and signal means connectedby said connection means to said source means; said relay responsivecontrol means and saidsignal means responsive to the condition of saidpair of conductors and said alarm actuated means depending upon theenergization of said relay means.

5. An alarm system, comprising: direct current source means includingconnection means connected to alarm actuated switching means in serieswith first relay means and further in series with second relay means;first diode means in parallel circuit with said first relay means andsecond diode means in parallel'circuit with said second relay means;said first and second diode means being oppositely polarized to eachother; said connection means including a pair of conductors over whichalarm signals are transmitted and which pair of conductors aresupervised; first asymmetric current conducting means connected inparallel circuit with said alarm actuated switching means; `said alarmactuated switching means further including alarm actuated contact meanshaving second asymmetric current conducting means substituted in placeof said first asymmetric current conducting means in reverse polarityupon the operation of said contact means; said contact means furtherincluding a grounded contact to ground one side of said source meansupon operation of said contact means; circuit polarity reversingcontacts including said connection means connected to said source meansto reversibly power said alarm actuated switching means and said firstand second relay means; and relay responsive control means including aground connection and signal means connected by said connection means tosaid source means; said relay responsive control means and said signalmeans responsive to the condition of said pair of conductors and saidalarm actuated switching means depending upon the energization of saidrelay means.

6. An alarm system, comprising: direct current source means includingconnection means connected through a plurality of alarm actuated meansin series circuit with polarized relay means; first asymmetric currentconducting means connected in parallel circuit with one of said alarmactuated means which is electrically most remote from said source means;each of said alarm actuated means further including alarm actuatedswitching means having second asymmetric current .conducting means whichcan be substituted in place of said first asymmetric current conductingmeans in reverse polarity upon the operation of one of `said alarmactuated means; circuit polarity reversing means including saidconnection means connected to said so-urce means to reversibly powersaid plurality of alarm actuated means and said polarized relay means;and relay responsive control means and lsignal means connected by saidconnection means to said source means and responsive to said operationof said polarized relay means to in turn operate said circuit polarityreversing means and said polarized relay means to activate said relayresponsive control means to thereby operate said signal means.

7. An alarm system, comprising: direct current source means includingconnection means connected through a plurality of alarm actuated meanswith first relay means and further with second relay means; first diodemeans in circuit with said rst relay means and second diode means incircuit with said second relay means; said first and second diode meansbeing oppositely polarized to each other; first asymmetric currentconducting means connected in parallel circuit with one of said alarmactuated means which is electrically most remote from said source means;each of said alarm actuated means further including alarm actuatedswitching means having second asymmetric current conducting meanssubstituted in place of said first asymmetric current conducting meansin reverse polarity upon the operation of one of, said alarm actuatedmeans; circuit polarity reversing means including said connection meansconnected to said source means to reversibly power said alarm actuatedmeans and said relay means; and relay responsive control means andsignal means connected by said connection means to said source means andresponsive to said operation of said first relay means to in turnoperate said circuit polarity reversing means and said second relaymeans to activate said relay responsive control means to thereby operatesaid signal means.

8. An alarm system, comprising: direct current source means includingconnection means connected through a plurality of alarm-actuated meansin series with polarized relay means; said connection means including apair of conductors over which alarm signals are transmitted with saidpair of conductors connected in series with said alarm actuated means;first asymmetric current conducting means connected in parallel circuitwith one of said alarm actuated means as a termination for said pair ofconductors; each of said alarm actuated means further including alarmIactuated switching means having second asymmetric current conductingmeans substituted in place of said rst asymmetric current conductingmeans in reverse polarity upon the operation of one of said alarmactuated means as a termination for said pair of conductors; each ofsaid switching means further including ground circ-uit means to groundsaid source means upon operation of one of said alarm actuated means;circuit polarity reversing means including said connection meansconnected to said source means to reversibly power said alarm actuatedmeans and said polarized relay means; and relay responsive control meansincluding a ground connection and signal means connected by saidconnection means to said source means; said relay responsive controlmeans and said signal means responsive to the condition of said pair of-cond-uctors and said alarm actuated means.

9. An alarm system, comprising: direct -current source means includingconnection means connected through a plurality of alarm actuated meansin series circuit with tirst relay means and further in series withsecond relay means; first diode means in parallel circuit with said rstrelay means and second diode means in parallel circuit with said secondrelay mean-s; said irst and second diode means being oppositelypolarized to each other; said connection means including a pair ofconductors over which alarm signals are transmitted and which isconnected in series with said plurality of alarm actuated means; rst

asymmetric current conducting means connected in parallel lcircuit withone of said alarm actuated means which is electrically most remote fromsaid source means; each of said alarm actuated means further includingalarm actuated `switching means having second asymmetric currentconducting means substituted in place of said rst asymmetric currentconducting means in reverse polarity upon the operation of one of saidalarm actuated means;

each of said switching means further including ground No referencescited.

THOMAS B. HABECKER, Primary Examiner.

D. L. TRAFTON, Assistant Examiner.

1. AN ALARM SYSTEM, COMPRISING: DIRECT CURRENT SOURCE MEANS INCLUDINGCONNECTION MEANS CONNECTED TO ALARM ACTUATED MEANS IN SERIES WITHPOLARIZED RELAY MEANS; SAID ALARM ACTUATED MEANS INCLUDING FIRSTASYMMETRIC CURRENT CONDUCTING MEANS; SAID ALARM ACTUATED MEANS FURTHERINCLUDING ALARM ACTUATED SWITCHING MEANS HAVING SECOND ASYMMETRICCURRENT CONDUCTING MEANS SUBSTITUTED IN PLACE OF SAID FIRST ASYMMETRICCURRENT CONDUCTING MEANS IN REVERSE POLARITY UPON THE OPERATION OF SAIDALARM ACTUATED MEANS; CIRCUIT POLARITY REVERSING MEANS INCLUDING SAIDCONNECTION MEANS CONECTED TO SAID SOURCE MEANS TO REVERSIBLY POWER SAIDALARM ACTUATED MEANS AND SAID POLARIZED RELAY MEANS; AND RELAYRESPONSIVE CONTROL MEANS AN SIGNAL MEANS CONNECTED BY SAID CONNECTIONMEANS TO SAID SOURCE MEANS AND RESPONSIVE TO SAID OPERATION OF SAIDPOLARIZED RELAY MEANS TO IN TURN OPERATE SAID CIRCUIT PORLARITYREVERSING MEANS AND SAID POLARIZED RELAY MEANS TO ACTIVATE SAID RELAYRESPONSIVE CONTROL MEANS TO THEREBY OPERATED SAID SIGNAL MEANS.